I use one of the auxilliary outputs to a small amplifier that sits under my chair. My Harmony remote is programmed to switch that aux output with the main output, and it has a volume control for it as well. Don’t know if such a setup is an option for you or not, but I rigged up something that works for me. BTW, my pre-pro is a Marantz 7701.
hell, now I can basically use mt SR7012 as a Heaphones amp if I wanted to!
I put a 100 ohm resistor in series with each headphone driver.
It would depend on what the power rating of your amplifier is and the impedance of your headphones. Mine is only 5W (homebrew), so it's not going to do much damage.
Sticking that size resistor in series with an 8 Ohm headphone changes the amp from a voltage source to a current source, drastically reducing the damping factor. I haven’t done any study of headphone drivers flopping around on their own, but it doesn’t seem like it would be an issue.
